Overhead power lines typically operate in a three-phase system, with each phase disposed on the pole in vertically spaced relation to one another. Each phase carries a number of ways. This arrangement requires group-actuated switches such that the corresponding ways in the phases can be simultaneously opened or closed. Typically, each switch includes a contact blade which extends from an electrical line mounted on an insulator carried by support structure on the pole for disconnection/connection with a contact member centrally located on the support structure in electrical contact with one or more other ways. The movable contact blades are group-operated or ganged together so that the switches of the three phases may be simultaneously disconnected or connected.
Commonly, vertical shafts carried by the support structure on the pole interconnect the movable switch blades such that, by rotating the vertical shafts, the blades may be moved between switch-open and switch-closed positions. One method for simultaneously opening and closing three disconnect/connect switches via the rotation of a single vertical shaft includes an electric motor mounted at the base of the pole. This traditional solution enables direct replacement of a manually-actuated handle with a motor operator. However, this is an expensive solution because of the requirement for transitional piping, couplings and guide plates between the motors and switches. Security also becomes an issue with the motors located close to ground level. Installation time, similarly, is longer and more costly. A second alternative for rotating the vertical shafts has included a hydraulic linear actuator. Hydraulic components, however, include expensive pumps, valves, cylinders and other miscellaneous equipment. Hydraulically-actuated systems have demonstrated unreliability caused by hydraulic leaks. Difficulties in setting up and adjusting the system are also encountered.